LED packaging structure and polychromatic light LED light source

Abstract

The utility model discloses an LED packaging structure and a polychromatic light LED light source, and the LED packaging structure comprises a substrate which is provided with a packaging surface, and the packaging surface is provided with electrodes which are arranged in pairs; the LED chip is mounted on the electrode; the fluorescent part is mounted on the light emitting surface of the LED chip; the packaging piece is mounted on the substrate and surrounds and is attached to the side surfaces of the LED chip and the fluorescent layer; the size of the end, attached to the LED chip, of the fluorescent piece is the same as the size of the light-emitting face of the LED chip. The LED light source has no yellow ring light spots, can cope with various secondary optical designs, and does not cause light spot chromatic aberration, so that the LED light source has high light color consistency and high reliability, and does not have the chromaticity problem after reflection and refraction.

Description

Technical Field

[0001] This utility model relates to the field of optoelectronic LED technology, and in particular to an LED packaging structure and a multi-color LED light source. Background Technology

[0002] The application of LED light sources in the automotive industry is becoming increasingly widespread, covering various aspects such as headlights, daytime running lights, turn signals, and brake lights. With the continuous advancement of intelligent technologies, the promotion of autonomous driving technology will also become an important trend in the automotive industry. Autonomous driving systems require blue-green light sources to provide a strong blue warning to pedestrians and other vehicles, thereby improving driving safety.

[0003] Although there are already LED light sources with multiple colors integrated, existing LED light sources will have color problems after being reflected and refracted by automotive optical components. Utility Model Content

[0004] The purpose of this invention is to improve the color problem that occurs after reflection and refraction when existing LED light sources are working, and to provide an LED packaging structure and a multi-color LED light source.

[0005] The technical solutions for achieving the above objectives include the following:

[0006] This utility model proposes an LED packaging structure, including

[0007] A substrate having a packaging surface on which a pair of electrodes are mounted;

[0008] An LED chip is mounted on the electrode;

[0009] A fluorescent element is mounted on the light-emitting surface of the LED chip;

[0010] A package is mounted on the substrate and surrounds and adheres to the sides of the LED chip and the phosphor layer;

[0011] The size of the end of the fluorescent element that is attached to the LED chip is the same as the size of the light-emitting surface of the LED chip.

[0012] In one embodiment, the electrode protrudes from the encapsulation surface, a groove is formed between the electrodes, the groove is filled with an insulating material to form a partition, the upper surface of the partition is close to or flush with the upper surface of the electrode, and the coefficient of thermal expansion of the insulating material is less than that of the white wall.

[0013] In one embodiment, the insulating material is filled in at least the portion of the area surrounding the electrode located below the LED chip.

[0014] In one embodiment, the fluorescent element is a fluorescent sheet or fluorescent film, and the shape of the fluorescent element is rectangular, inverted trapezoidal, or polygonal.

[0015] In one embodiment, the upper surface of the package is flush with or lower than the upper surface of the fluorescent element.

[0016] In one embodiment, the insulating material is one or more of polytetrafluoroethylene, ceramic materials, glass fiber, aluminum silicate, and polyimide.

[0017] In one embodiment, the substrate is one of an aluminum nitride substrate, an aluminum oxide substrate, or a silicon substrate.

[0018] In one embodiment, a Zener diode is also mounted on the substrate, and two pairs of electrodes are arranged in pairs on the packaging surface. The Zener diode is mounted on one pair of electrodes and is connected in parallel with the LED chip.

[0019] This utility model also proposes a multicolor LED light source, comprising: at least two of the above-mentioned LED packaging structures, wherein the materials of the phosphors in all LED packaging structures can be divided into at least two categories.

[0020] In one embodiment, a control circuit corresponding to the LED chip of each of the LED package structures is also included, and the control circuits are independent of each other.

[0021] The technical solution provided by this utility model has the following advantages and effects:

[0022] In the LED packaging structure of this utility model, the size of the end of the phosphor element that is attached to the LED chip is the same as the size of the light-emitting surface of the LED chip, there is no yellow ring light spot, and it can cope with various secondary optical designs without causing light spot color difference, so that the LED light source has high light color consistency and high reliability, and there will be no color problem after reflection and refraction.

[0023] This utility model's multi-color LED light source integrates multiple colors of light, reduces LED size, simplifies LED models significantly, facilitates selection, and features high color consistency and high reliability. Attached Figure Description

[0024] The accompanying drawings illustrate specific examples of the technical solutions described in this utility model, and together with the detailed embodiments, form part of the specification, serving to explain the technical solutions, principles, and effects of this utility model.

[0025] Unless otherwise specified or defined, the same reference numerals in different figures represent the same or similar technical features, and different reference numerals may be used to represent the same or similar technical features.

[0026] Figure 1 This is a schematic diagram of the first embodiment of the LED packaging structure of this utility model;

[0027] Figure 2 This is a schematic diagram of the second embodiment of the LED packaging structure of this utility model;

[0028] Figure 3 This is a schematic diagram of the third embodiment of the LED packaging structure of this utility model;

[0029] Figure 4 This is a schematic diagram of the first embodiment of the multicolor LED light source of this utility model;

[0030] Figure 5 for Figure 4 Top view of the embodiment;

[0031] Figure 6 This is a schematic diagram of the second embodiment of the multicolor LED light source of this utility model;

[0032] Figure 7 This is a schematic diagram of the third embodiment of the multicolor LED light source of this utility model;

[0033] Figure 8 This is a top view of the fourth embodiment of the multicolor LED light source of this utility model;

[0034] Figure 9 This is a top view of the fifth embodiment of the multicolor LED light source of this utility model.

[0035] Explanation of reference numerals in the attached figures:

[0036] 100. LED packaging structure; 110. Substrate; 111. Electrode; 112. Packaging surface; 113. Trench; 114. Spacer; 115. Insulating layer; 116. Zener diode; 120. LED chip; 121. Light-emitting surface; 130. Phosphor element; 140. Packaging component.

[0037] 200. Multi-color LED light source. Detailed Implementation

[0038] To facilitate understanding of this utility model, the specific embodiments of this utility model will be described in more detail below with reference to the accompanying drawings.

[0039] Unless otherwise specified or defined, the terms "first," "second," etc., used in this document are for distinguishing names only and do not represent a specific number or order.

[0040] Unless otherwise stated or defined, the term “and / or” as used herein includes any and all combinations of one or more of the associated listed items.

[0041] It should be noted that when a component is considered "fixed" to another component, it can be directly fixed to the other component or there can be an intervening component; when a component is considered "connected" to another component, it can be directly connected to the other component or there can be an intervening component; when a component is considered "mounted" on another component, it can be directly mounted on the other component or there can be an intervening component; when a component is considered "placed" on another component, it can be directly placed on the other component or there can be an intervening component.

[0042] Currently, during the LED packaging process, a white wall adhesive needs to be sprayed around the four sides of the LED chip and the sides of the phosphor sheet. After the white wall adhesive solidifies, it forms a white wall to protect the LED chip. Because there is a gap at the bottom of the LED chip, the white wall adhesive can seep into the bottom of the chip. When the LED light source is working, the LED chip generates heat, causing the white wall to generate a thermal effect. The white wall continuously applies bottom stress to the LED chip, reducing the reliability of the LED light source and shortening its lifespan.

[0043] This invention fills the space between the electrodes of the substrate with an insulating material that has an ultra-low coefficient of thermal expansion. This material can significantly reduce the thermal stress generated at the bottom of the LED chip after it heats up, thereby effectively improving the reliability and lifespan of the LED light source.

[0044] like Figure 1 , Figure 2 and Figure 3As shown, this embodiment first provides an LED packaging structure 100, including a substrate 110, an LED chip 120, a phosphor element 130, and a package 140. The substrate 110 can be a ceramic substrate (such as an aluminum nitride or alumina substrate) or a silicon substrate; in this embodiment, it is a ceramic substrate. The substrate 110 supports the LED chip 120, the phosphor element 130, and the package 140. Pairs of electrodes 111 are provided on both the upper and lower surfaces of the substrate 110, with the upper surface serving as the packaging surface 112. The LED chip 120 is flip-chip bonded to the electrode pair on the upper surface, and the positive and negative electrodes of the LED chip 120 are correspondingly connected to the positive and negative electrodes of the substrate 110. The electrode pair on the lower surface of the substrate 110 is used to bond the LED packaging structure 100 to an external substrate. The electrodes 111 on at least the upper surface of the substrate 110 have a certain thickness, being higher than the surface of the substrate 110, i.e., the electrodes 111 protrude beyond the packaging surface 112. To simplify the electroplating process, the electrode pairs on both the upper and lower surfaces of the substrate 110 can also have a certain thickness. A height difference exists between the electrode pair and the encapsulation surface 112 of the substrate 110, forming a trench 113. The trench 113 is filled with an environmentally friendly insulating material with an extremely low coefficient of thermal expansion, such as one or more of polytetrafluoroethylene, ceramic materials, glass fiber, aluminum silicate, and polyimide. The insulating material is preferably white. The insulating material forms a barrier 114, the upper surface of which is close to, or slightly lower than, the upper surface of the electrode 111 or flush with it. This prevents the white wall adhesive from entering the trench 113. Furthermore, due to the very low coefficient of thermal expansion of the insulating material, it exerts almost no bottom stress on the LED chip 120 when the LED light source is heating up. This solves the problem of traditional white wall adhesive entering the bottom of the LED chip 120 and continuously exerting bottom stress during heating, effectively improving the reliability and lifespan of the LED light source.

[0045] In the area surrounding electrode 111, besides the aforementioned trench 113, there is a portion located below the LED chip 120. Although the thermal effect in these areas is weaker than that in the trench 113, insulating material can still be filled in these areas to further reduce stress. In this embodiment, for the sake of process simplicity, insulating material is filled around the periphery of electrode 111 on the encapsulation surface 112 to form an insulating layer 115.

[0046] To protect the LED chip 120, a Zener diode 116 is also installed on the package surface 112. Specifically, there are two pairs of electrodes 111 arranged in pairs on the package surface 112. The Zener diode 116 is flip-chip soldered onto one pair of electrodes, and the LED chip 120 is flip-chip soldered onto the other pair of electrodes. The Zener diode 116 and the LED chip 120 are connected in parallel to protect the chip. At this time, there are also grooves between the corresponding electrode pairs of the Zener diode 116. In order to improve the reliability of the LED light source, the grooves between the corresponding electrode pairs of the Zener diode 116 are also filled with the aforementioned insulating material to prevent the white wall adhesive from entering the middle position of the Zener diode 116 electrodes and reduce the bottom stress of the Zener diode 116. It should be noted that if the application does not require a Zener diode, it is not necessary to install one.

[0047] In this embodiment, the bottom of the LED chip 120 and Zener tube 116 is not in contact with a high-expansion-coefficient, highly reflective white wall. The thermal expansion coefficient of the insulating material is extremely low, less than that of the white wall, which reduces the thermal stress generated by the LED chip 120 during operation and reduces the damage to the LED chip 120 and Zener tube 116 caused by the stress at the bottom of the LED chip 120 and Zener tube 116, thereby improving the reliability and service life of the LED light source.

[0048] In this embodiment, the LED chip 120 is a blue LED chip. The light emission direction of the LED chip 120 is upward, that is, the upper surface of the LED chip 120 is the light-emitting surface 121. A phosphor element 130 is attached to the light-emitting surface 121. The phosphor element 130 can absorb the blue light emitted by the LED chip 120 and convert it into light of other wavelengths. Different phosphor materials can be used to achieve different color light emission effects. The phosphor element 130 can be a phosphor sheet or a phosphor film.

[0049] As the optical design of automotive lighting becomes increasingly diversified, the application of various optical components is also becoming more widespread. These optical components require that the color of the LED light source remain visually consistent during the refraction or reflection of light, with no visible color difference. The requirements for LED light color consistency are constantly increasing. Designers need to ensure color consistency of the light source while meeting diverse lighting needs to improve overall lighting effects and safety. Therefore, in this embodiment, the size of the end of the phosphor element 130 that is attached to the LED chip 120 is designed to be the same as the size of the light-emitting surface 121 of the LED chip 120; that is, the length and width of the LED chip 120 and the length and width of the contact surface between the phosphor element 130 and the LED chip 120 are exactly the same. This ensures that when the phosphor element 130 is excited, the blue light travels the same distance within the phosphor element 130. The entire surface of the phosphor element 130 is broken down into countless points. After the blue light mixes with the phosphor powder within the phosphor element 130, the color temperature of each point is the same or close. The color temperature distribution of each point on the entire surface of the phosphor element 130 is uniform, and after reflection and refraction by the automotive optical components, no colorimetric problems will occur. In other words, the color temperature of the entire surface of the phosphor 130 is uniform, forming a high-quality light spot with highly consistent color. Compared with the light spot of traditional LED packaging structure, which is whiter in the middle and yellower around the edges, the light spot quality is significantly improved. It can cope with various secondary optical designs without color difference.

[0050] Although the dimensions of the contact surface between the phosphor element 130 and the LED chip 120 are the same as the dimensions of the light-emitting surface 121 of the LED chip 120, the dimensions of the other parts of the phosphor element 130 are not limited. Therefore, the shape of the phosphor element 130 is not limited to... Figure 1 The rectangle in the image can be... Figure 2 The inverted trapezoid or Figure 3 Polygons, etc., are used to obtain high-quality light spots.

[0051] A package 140 is also provided on the substrate 110, which surrounds and adheres to the sides of the LED chip 120 and the phosphor element 130. In this embodiment, the package 140 is a highly reflective white wall, which fills, surrounds, and contacts the four sides of the LED chip 120 and the sides of the phosphor element 130 by means of dispensing, local spraying, etc., and covers the Zener tube 116. The upper surface of the highly reflective white wall is flush with or lower than the upper surface of the phosphor element 130. Therefore, the four sides of the LED chip 120 are wrapped by the highly reflective white wall, and the bottom is filled with insulating material, so that the blue light of the LED chip 120 can only be emitted from directly above.

[0052] The complete packaging process of this embodiment is as follows: An insulating material is filled between the electrodes 111 on the substrate 110. The insulating material can be flush with or slightly lower than the surface of the electrodes 111. A flip-chip LED 120 is soldered onto the electrodes 111, with the positive and negative electrodes of the LED chip 120 correspondingly connected to the positive and negative electrodes of the substrate 110. Simultaneously, a flip-chip Zener diode 116 can be installed, with its positive and negative terminals correspondingly connected to the positive and negative terminals of the substrate 110. The Zener diode 116 is connected to the LED chip 120 through a working circuit, providing protection. LED chip 120; fluorescent elements 130 of different colors, such as phosphor sheets or phosphor films, are attached to the surface of the flip-chip LED chip 120, and the size of the contact surface between the phosphor element 130 and the LED chip 120 is exactly the same as the upper surface of the LED chip 120; a layer of high-reflectivity white wall is filled by means of dispensing, local spraying, etc. The filled high-reflectivity white wall surrounds the four sides of the LED chip 120 and the sides of the phosphor sheet or phosphor film, and the surface of the high-reflectivity white wall is flush with or slightly lower than the upper surface of the phosphor sheet or phosphor film.

[0053] In summary, in this embodiment, because the bottom of the LED chip is filled with insulating material, the flow of the high-reflectivity white wall is blocked, preventing the white wall from penetrating to the bottom of the LED chip and Zener diode. This significantly reduces the stress caused by the expansion of the high-reflectivity white wall due to heat during LED light source operation, preventing stress damage to the LED chip and Zener diode, thereby improving their lifespan. Furthermore, the LED chip size and the contact surface size between the phosphor and the LED chip are the same, achieving a yellow-ring-free light spot and enabling various secondary optical designs without causing color difference in the light spot, resulting in high color consistency and high reliability of the LED light source.

[0054] Based on the above LED packaging structure, this embodiment also provides a multi-color LED light source 200, such as... Figures 4-9As shown, the LED package structure 200 includes at least two of the aforementioned LED package structures 100. The substrate 110 of all LED package structures 100 is a single piece. The phosphors 130 of all LED package structures 100 are made of at least two different materials. Phosphors 130 made of different materials can achieve different color emission effects. Therefore, the multicolor LED light source 200 integrates multiple colors of light. Adjacent LED chips 120 have no electrical connection. Each LED chip 120 of each LED package structure 100 corresponds to an independent control circuit. The independent control circuit means that each color has its own control circuit to control the emission color of the LED light source 200. In other words, a single multi-color LED light source 200, combined with a phosphor sheet or phosphor film, can be mixed to create different color temperatures, forming different colors such as white light, amber light, and blue-green light. Different colors of light are used for different purposes in automotive lighting; for example, white light can be used as daytime running lights, amber light as turn signals, and blue-green light as autonomous driving indicator lights. Depending on customer needs, phosphor sheets or films of two or more colors can be manufactured, and these different colors of light can be combined on a ceramic substrate. Figure 5 The two shown Figure 8 and Figure 9 The three shown are combined and finally packaged into a finished product, realizing the integration of multiple colors of light in one product.

[0055] By integrating multiple colors into a single LED light source, a single LED can provide multiple colors of light, and each color can operate independently. This significantly simplifies LED model designations, reduces LED package size, simplifies LED selection, and improves SMT (Surface Mount Technology) efficiency. Furthermore, the LED packaging structure of this invention extends the lifespan of the LED light source, ensuring that the color temperature is uniform or extremely close at every point on the entire emitting surface. Even after optical design, the LED light source still exhibits excellent light spot quality.

[0056] It should be noted that the phosphors in all LED package structures of a multicolor LED light source can have the same shape or be a combination of multiple shapes. For example, the phosphor in an LED package structure that emits blue light is rectangular, while the phosphor in an LED package structure that emits green light is an inverted trapezoid.

[0057] In summary, the multi-color LED light source of this invention integrates multiple colors of light, reduces the size of the LED, simplifies LED models by a factor of two, facilitates selection, and has high color consistency and high reliability.

[0058] When referencing drawings, new features are explained. To avoid redundant references to drawings that would make the description less concise, features already described will not be referenced again on the drawings if the description is clear.

[0059] The purpose of the above embodiments is to reproduce and derive the technical solution of this utility model by way of example, and to fully describe the technical solution, purpose and effect of this utility model. The purpose is to enable the public to have a more thorough and comprehensive understanding of the disclosed content of this utility model, and it is not intended to limit the protection scope of this utility model.

[0060] The above embodiments are not an exhaustive list based on the present invention, and there may be other embodiments not listed. Any substitutions and improvements made without departing from the concept of the present invention are within the protection scope of the present invention.

Claims

1. An LED package structure, characterized in that, The application relates to an LED encapsulation structure, which comprises: a substrate with an encapsulation surface on which a pair of electrodes are arranged; an LED chip arranged on the electrodes; a fluorescent piece arranged on the light-emitting surface of the LED chip; an encapsulation piece arranged on the substrate and adhered to the side surface of the LED chip and the fluorescent piece; the size of the end of the fluorescent piece adhered to the LED chip is the same as that of the light-emitting surface of the LED chip.

2. The LED package structure of claim 1, wherein, The electrodes protrude from the encapsulation surface, and a groove is formed between the electrodes, which is filled with an insulating material to form a barrier piece, the upper surface of the barrier piece is flush with the upper surface of the electrodes, and the thermal expansion coefficient of the insulating material is smaller than that of a white wall.

3. The LED package structure of claim 2, wherein, In the peripheral area of the electrodes, at least the part below the LED chip is filled with the insulating material.

4. The LED package structure of claim 2, wherein, The insulating material is one of polytetrafluoroethylene, ceramic material, glass fiber, aluminum silicate and polyimide.

5. The LED package structure of claim 1, wherein the phosphor layer is disposed on the LED chip. The fluorescent piece is a fluorescent sheet or a fluorescent film, and the shape of the fluorescent piece is rectangular or inverted trapezoidal.

6. The LED package structure of claim 1, wherein, The upper surface of the encapsulation piece is flush with or lower than the upper surface of the fluorescent piece.

7. The LED package structure of claim 1, wherein the phosphor layer is disposed on the LED chip. The substrate is one of an aluminum nitride substrate, an aluminum oxide substrate or a silicon substrate.

8. The LED package structure of any one of claims 1-7, wherein, A Zener diode is arranged on the substrate, and the electrodes arranged on the encapsulation surface are divided into two pairs, the Zener diode is arranged on one pair of electrodes, and the Zener diode is connected in parallel with the LED chip.

9. Multi-colour LED light source, characterized in that The application further relates to a LED encapsulation structure group comprising at least two LED encapsulation structures as claimed in any one of claims 1-8, and the materials of the fluorescent pieces of all the LED encapsulation structures are at least divided into two categories.

10. The multi-colored LED light source of claim 9, wherein, The application further relates to a control circuit corresponding to the LED chip of each LED encapsulation structure, and the control circuits are independent of each other.

Images